Dynamic internet protocol addressing solutions with network-based mobility

ABSTRACT

A media access gateway includes a wireless network interface, an address assignment module, a proxy mobility agent module, and a profile module. The wireless network interface establishes a link with a wireless terminal. The address assignment module receives an address request message, including a mobility signal, from the wireless terminal. The proxy mobility agent module selectively transmits a proxy binding update to a local mobility anchor, and receives a proxy binding acknowledgement. The address assignment module transmits an address assignment message to the wireless terminal in response to the mobility signal indicating support or preference for proxy mobility. The address assignment message is based on address information in the proxy binding acknowledgement. The profile module retrieves a profile for the wireless terminal from a server. The address assignment module selectively transmits a second address assignment message to the wireless terminal based on the address information in the profile.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/954,119, filed on Aug. 6, 2007, and U.S. Provisional Application No.60/973,258, filed on Sep. 18, 2007. The disclosures of the aboveapplications are incorporated herein by reference in their entirety.

FIELD

The subject matter of the present disclosure relates to network-basedmobility and more particularly to dynamic internet protocol addressingsolutions within a framework of network-based mobility.

BACKGROUND

The background description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent the work is described in thisbackground section, as well as aspects of the description that may nototherwise qualify as prior art at the time of filing, are neitherexpressly nor impliedly admitted as prior art against the presentdisclosure.

Referring now to FIG. 1, a functional block diagram of a wirelesscommunications system is presented. A home network 102 receives packetsfrom and sends packets to a distributed communications system 104, suchas the Internet. A wireless terminal 106 wirelessly connects to the homenetwork 102. For example only, the wireless terminal 106 may be a mobilephone, and the home network 102 may be the cellular network of a mobilephone operator.

The wireless terminal 106 is configured to work with the home network102, and may be unable to connect to the networks of other carriers. Invarious implementations, the wireless terminal 106 may be able to viewcontent from the distributed communications system 104 via the homenetwork 102. The home network 102 may interconnect with the networks ofother service providers and/or core networks.

Referring now to FIG. 2, a functional block diagram of a wirelesscommunications system offering mobility is presented. The home network102 is connected to one or more visited networks 110. For example only,FIG. 2 depicts three visited networks 110-1, 110-2, and 110-3. Invarious implementations, the visited networks 110 may be the networks ofother service providers, including service providers in other countries.

A mobile wireless terminal 120 includes mobility features that allow themobile wireless terminal 120 to communicate with the visited networks110. For example, in FIG. 2, the mobile wireless terminal 120 hasestablished a wireless connection to the visited network 110-1. Themobile wireless terminal 120 includes the code and data used tocommunicate with the home network 102 via the visited network 110-1. Inthis way, the mobile wireless terminal 120 can interface with the homenetwork 102 even when connected to one of the visited networks 110.Because the mobile wireless terminal 120 itself includes mobilityfeatures, the mobile wireless terminal 120 may be described assupporting client mobile internet protocol (CMIP).

For example, mobile internet protocol (IP) for IP version 6 (IPv6) isdescribed in request for comment (RFC) 3775, titled “Mobility Support inIPv6,” the disclosure of which is hereby incorporated by reference inits entirety. Mobile IP for IP version 4 (IPv4) is described in RFC3344, entitled “IP Mobility Support for IPv4,” the disclosure of whichis hereby incorporated by reference in its entirety.

Referring now to FIG. 3, a functional block diagram depicts a wirelesscommunications system that provides proxy mobility to the wirelessterminal 106. A home network 150 communicates with visited networks160-1, 160-2, and 160-3. The visited networks 160 provide transparentmobility to wireless terminals, such as the wireless terminal 106, whichdo not include mobility functionality. This may be referred to as proxymobile IP (PMIP) or network mobile IP. Proxy mobility in IPv6 isdescribed in an Internet Engineering Task Force (IETF) draft titled“Proxy Mobile IPv6” (published Jun. 18, 2007 and available as“draft-ietf-netlmm-proxymip6-01.txt”), the disclosure of which is herebyincorporated by reference in its entirety.

When the wireless terminal 106 attempts to establish a link with thevisited network 160-1, the visited network 160-1 determines the networkto which the wireless terminal 106 belongs. In this case, the visitednetwork 160-1 determines that the home network 150 is the appropriatenetwork. The visited network 160-1 then forwards packets from thewireless terminal 106 to the home network 150 and passes packets fromthe home network 150 to the wireless terminal 106. The wireless terminal106 can therefore be oblivious to the fact that the wireless terminal106 is connected to the visited network 160-1 instead of to the homenetwork 150.

Referring now to FIG. 4, a functional block diagram and timeline of animplementation of client mobility is presented. The home network 102includes a home agent (HA) 180. The HA 180 establishes the logicallocation of the mobile wireless terminal 120. Packets ultimatelydestined for the mobile wireless terminal 120 are sent to the HA 180,while packets from the mobile wireless terminal 120 will appear tooriginate from the location of the HA 180.

The mobile wireless terminal 120 may establish a connection to an accessrouter (AR) 182 within the visited network 110-1. In variousimplementations, additional ARs (not shown) may be present. The AR 182may communicate with other networks, including the home network 102.

When the mobile wireless terminal 120 connects to the visited network110-1, the mobile wireless terminal 120 performs authentication andauthorization with the AR 182. This may include communicating with anauthentication, authorization, and accounting (AAA) server. The AAAserver may retrieve information based on an identifier of the mobilewireless terminal 120, such as a network address identifier, thatuniquely identifies the mobile wireless terminal 120. The AAA server mayindicate to the AR 182 whether the mobile wireless terminal 120 shouldbe allowed access and what services should be provided.

The mobile wireless terminal 120 receives a local address from the AR182. Using this address, the mobile wireless terminal 120 cancommunicate with various network elements, including the HA 180. Themobile wireless terminal 120 transmits a binding update message to theHA 180. The HA 180 allocates a global home address HoA to the mobilewireless terminal 120. The HA 180 may create a binding cache entry thatrecords information about the mobile wireless terminal 120, such as thecurrent address of the mobile wireless terminal 120 and the allocatedaddress HoA.

The HA 180 transmits a binding acknowledgement message to the mobilewireless terminal 120. The binding acknowledgement message includes HoAso that the mobile wireless terminal 120 is aware of its global homeaddress. Packets sent from other network devices, such as other wirelessterminals, are sent to that home address. The HA 180 receives thosepackets and forwards them to the mobile wireless terminal 120.Similarly, packets from the mobile wireless terminal 120 are first sentto the HA 180. The HA 180 then forwards the packets with a sourceaddress of HoA. To allow for packets to be exchanged between the mobilewireless terminal 120 and the HA 180, a tunnel is established betweenthe mobile wireless terminal 120 and the HA 180.

Referring now to FIG. 5, a functional block diagram and timeline of animplementation of proxy mobility is presented. The wireless terminal 106may establish a connection to a media access gateway (MAG) 190 in thevisited network 160-1. In various implementations, additional MAGs (notshown) may be present in the visited network 160-1. The MAG 190 maycommunicate with other networks, including the home network 150.

Once the wireless terminal 106 connects, the MAG 190 may authenticatethe wireless terminal 106 and determine what services the wirelessterminal 106 is authorized to access. The wireless terminal 106 thenrequests an address from the MAG 190. The MAG 190 determines a localmobility anchor (LMA) to which the wireless terminal 106 belongs. Forexample only, the MAG 190 may consult a home subscriber server (HSS) todetermine the appropriate LMA.

The MAG 190 then sends a proxy binding update identifying the wirelessterminal 106 to the identified LMA, which in this case is LMA 192,located in the home network 150. The LMA 192 allocates a home addressHoA for the wireless terminal 106. The LMA 192 may also create a bindingcache entry to record information about the wireless terminal 106. TheLMA 192 sends a proxy binding acknowledgement including HoA to the MAG190.

The MAG 190 and the LMA 192 establish a tunnel for transfer of packetsto and from the wireless terminal 106. The MAG 190 then assigns HoA tothe wireless terminal 106. When the wireless terminal 106 transmits apacket, the MAG 190 sends that packet through the tunnel to the LMA 192.The LMA 192 then forwards the packet with a source address of HoA. Whena packet arrives at the LMA 192 with a destination address of HoA, theLMA 192 sends the packet to the MAG 190 through the tunnel. The MAG 190then forwards the packets to the wireless terminal 106.

Using this architecture, the wireless terminal 106 can be unaware of themobility services provided by the MAG 190. As expected, the wirelessterminal 106 has been assigned a home address in the home network 150.The wireless terminal 106 therefore does not need to be aware that it isactually connected to the visited network 160-1 instead of to the homenetwork 150.

Referring now to FIGS. 6-8, exemplary message flow diagrams arepresented for various methods of obtaining a layer 3 address (e.g., anIP address). In FIG. 6, an example of dynamic host configurationprotocol (DHCP) is shown. DHCP may be used to obtain an IPv4 address oran IPv6 address. DHCP for IPv4 is described in RFC 2131, titled “DynamicHost Configuration Protocol,” the disclosure of which is herebyincorporated by reference in its entirety. DHCP for IPv6 is described inRFC 3315, titled “Dynamic Host Configuration Protocol for IPv6(DHCPv6),” the disclosure of which is hereby incorporated by referencein its entirety.

After a wireless terminal establishes layer 2 connectivity with anaccess router, the wireless terminal may broadcast a DHCP request. Theaccess router can then provide the wireless terminal with an address viaa DHCP reply. In various implementations, a two-stage process may beperformed, where two requests and two replies are sent. The initialrequest may be a discovery message and the initial reply may be an offermessage. A subsequent request indicates an acceptance of the offer ofthe address and a subsequent reply indicates that the access routeracknowledges the request. This subsequent reply may provide additionalconfiguration information, such as domain name server (DNS) addresses.

Referring now to FIG. 7, a timeline depicts exemplary stateless IPaddress autoconfiguration. Stateless autoconfiguration for IPv6 isdescribed in RFC 2462, titled “IPv6 Stateless Autoconfiguration,” thedisclosure of which is hereby incorporated by reference in its entirety.After the wireless terminal establishes layer 2 connectivity with anaccess router, the wireless terminal broadcasts a router solicitationmessage. The access router can then respond with a router advertisement,which includes an address prefix. The prefix may be local to the accessrouter's network or may be globally routable.

The wireless terminal configures a full IPv6 address based on theprovided prefix. For example only, a provided prefix may be a 64-bitvalue, and the wireless terminal creates a 128-bit IPv6 address usingthe prefix and a 64-bit value based on an interface identifier of thewireless terminal. For example only, the interface identifier mayinclude a media access control (MAC) address.

The wireless terminal may then verify that the created address isunique, at least within the access router's network. The wirelessterminal may determine uniqueness by broadcasting a neighbor discoverymessage that includes the created address. If no neighbors respond, thewireless terminal assumes that no other network node is using thecreated address. Neighbor discovery is described in RFC 2461, titled“Neighbor Discovery for IP Version 6 (IPv6),” the disclosure of which ishereby incorporated by reference in its entirety.

Referring now to FIG. 8, an exemplary message diagram depicts a scenariowhere the wireless terminal attempts to use stateless addressautoconfiguration but the access router requires the use of DHCP. Afterlayer 2 connectivity is established, the wireless terminal broadcasts arouter solicitation message. The access router responds with a routeradvertisement message indicating that DHCP is required. For exampleonly, this may be indicated by setting an ‘M’ flag or an ‘O’ flag in therouter advertisement message. In order to obtain a layer 3 address, thewireless terminal responds by broadcasting a DHCP request. The accessrouter can then assign an address to the wireless terminal and providethat address to the wireless terminal in a DHCP reply.

SUMMARY

A media access gateway comprises a wireless network interface, anaddress assignment module, and a proxy mobility agent module. Thewireless network interface establishes a wireless link with a wirelessterminal. The address assignment module receives an address requestmessage, which includes a mobility signal from the wireless terminal.The proxy mobility agent module selectively transmits a proxy bindingupdate to a local mobility anchor and receives a proxy bindingacknowledgement from the local mobility anchor. The address assignmentmodule selectively transmits an address assignment message to thewireless terminal when the mobility signal indicates proxy mobility. Theaddress assignment message is based on address information in the proxybinding acknowledgement.

The address request message comprises at least one of a dynamic hostconfiguration protocol (DHCP) message and a router solicitation message.The address assignment message comprises at least one of a DHCP messageand a router advertisement message. The media access gateway furthercomprises a profile module that retrieves a profile corresponding to thewireless terminal from a server. When the profile includes addressinformation for the wireless terminal, the address assignment moduletransmits a second address assignment message to the wireless terminalbased on the address information in the profile.

The proxy mobility agent module omits transmitting the addressassignment message when the address information in the proxy bindingacknowledgement matches the address information in the profile. Theproxy mobility agent module determines an address of the local mobilityanchor from the profile. The address assignment module receives a secondaddress request message including a mobility request signal prior toreceiving the address request message. After receiving the secondaddress request message, the address assignment module transmits asecond address assignment message to the wireless terminal. The secondaddress assignment message includes a mobility availability signal.

The address request message includes an extended access point name (APN)field. The extended APN field includes the mobility signal and an APNthat identifies a packet data network connected to the local mobilityagent. The address assignment message includes an extended access pointname (APN) field. The extended APN field includes a mobilityavailability signal and an APN that identifies a packet data networkconnected to the local mobility agent.

A communications system comprises the media access gateway of and awireless terminal, which comprises a second wireless network interfaceand an address determination module. The address determination moduletransmits the address request message via the second wireless networkinterface and receives the address assignment message via the secondwireless network interface. The wireless terminal further comprises athird wireless network interface. The address determination moduleincludes a same address signal in the address request message. The sameaddress signal indicates that the second and third wireless networkinterfaces can be assigned a single address. The proxy mobility agentmodule forwards the same address signal to the local mobility anchor.

A media access gateway comprises wireless network interfacing means forestablishing a wireless link with a wireless terminal; addressassignment means for receiving an address request message, the addressrequest message including a mobility signal from the wireless terminal;and proxy mobility agent (PMA) means for selectively transmitting aproxy binding update to a local mobility anchor and receiving a proxybinding acknowledgement from the local mobility anchor. The addressassignment means selectively transmits an address assignment message tothe wireless terminal when the mobility signal indicates proxy mobility.The address assignment message is based on address information in theproxy binding acknowledgement.

The address request message comprises at least one of a dynamic hostconfiguration protocol (DHCP) message and a router solicitation message;and the address assignment message comprises at least one of a DHCPmessage and a router advertisement message. The media access gatewayfurther comprises profile means for retrieving a profile correspondingto the wireless terminal from a server. When the profile includesaddress information for the wireless terminal, the address assignmentmeans transmits a second address assignment message to the wirelessterminal based on the address information in the profile.

The PMA means omits transmitting the address assignment message when theaddress information in the proxy binding acknowledgement matches theaddress information in the profile. The PMA means determines an addressof the local mobility anchor from the profile. The address assignmentmeans receives a second address request message including a mobilityrequest signal prior to receiving the address request message. Afterreceiving the second address request message, the address assignmentmeans transmits a second address assignment message to the wirelessterminal. The second address assignment message includes a mobilityavailability signal.

The address request message includes an extended access point name (APN)field. The extended APN field includes the mobility signal and an APNthat identifies a packet data network connected to the local mobilityagent. The address assignment message includes an extended access pointname (APN) field. The extended APN field includes a mobilityavailability signal and an APN that identifies a packet data networkconnected to the local mobility agent.

A communications system comprises the media access gateway and awireless terminal, which comprises second wireless network interfacingmeans for establishing the wireless link with the media access gatewayand address determination means for transmitting the address requestmessage via the second wireless network interfacing means and forreceiving the address assignment message via the second wireless networkinterfacing means.

The wireless terminal further comprises third wireless networkinterfacing means for establishing a second wireless link. The addressdetermination means includes a same address signal in the addressrequest message. The same address signal indicates that the second andthird wireless network interfacing means can be assigned a singleaddress. The PMA means forwards the same address signal to the localmobility anchor.

A method comprises establishing a wireless link with a wirelessterminal; receiving an address request message, the address requestmessage including a mobility signal from the wireless terminal;selectively transmitting a proxy binding update to a local mobilityanchor; receiving a proxy binding acknowledgement from the localmobility anchor; and selectively transmitting an address assignmentmessage to the wireless terminal when the mobility signal indicatesproxy mobility. The address assignment message is based on addressinformation in the proxy binding acknowledgement.

The address request message comprises at least one of a dynamic hostconfiguration protocol (DHCP) message and a router solicitation message;and the address assignment message comprises at least one of a DHCPmessage and a router advertisement message. The method further comprisesretrieving a profile corresponding to the wireless terminal from aserver. The method further comprises when the profile includes addressinformation for the wireless terminal, transmitting a second addressassignment message to the wireless terminal based on the addressinformation in the profile.

The method further comprises omitting transmitting the addressassignment message when the address information in the proxy bindingacknowledgement matches the address information in the profile. Themethod further comprises determining an address of the local mobilityanchor from the profile. The method further comprises receiving a secondaddress request message including a mobility request signal prior toreceiving the address request message. The method further comprisesafter receiving the second address request message, transmitting asecond address assignment message to the wireless terminal. The secondaddress assignment message includes a mobility availability signal.

The address request message includes an extended access point name (APN)field. The extended APN field includes the mobility signal and an APNthat identifies a packet data network connected to the local mobilityagent. The address assignment message includes an extended access pointname (APN) field. The extended APN field includes a mobilityavailability signal and an APN that identifies a packet data networkconnected to the local mobility agent. The method further comprisesincluding a same address signal in the address request message. The sameaddress signal indicates that multiple wireless network interfaces ofthe wireless terminal can be assigned a single address; and forwardingthe same address signal to the local mobility anchor.

A computer program stored on a computer-readable medium for use by aprocessor, where the computer program comprises establishing a wirelesslink with a wireless terminal; receiving an address request message, theaddress request message including a mobility signal from the wirelessterminal; selectively transmitting a proxy binding update to a localmobility anchor; receiving a proxy binding acknowledgement from thelocal mobility anchor; and selectively transmitting an addressassignment message to the wireless terminal when the mobility signalindicates proxy mobility. The address assignment message is based onaddress information in the proxy binding acknowledgement.

The address request message comprises at least one of a dynamic hostconfiguration protocol (DHCP) message and a router solicitation message;and the address assignment message comprises at least one of a DHCPmessage and a router advertisement message. The computer program furthercomprises retrieving a profile corresponding to the wireless terminalfrom a server. The computer program further comprises when the profileincludes address information for the wireless terminal, transmitting asecond address assignment message to the wireless terminal based on theaddress information in the profile.

The computer program further comprises omitting transmitting the addressassignment message when the address information in the proxy bindingacknowledgement matches the address information in the profile. Thecomputer program further comprises determining an address of the localmobility anchor from the profile. The computer program further comprisesreceiving a second address request message including a mobility requestsignal prior to receiving the address request message. The computerprogram further comprises after receiving the second address requestmessage, transmitting a second address assignment message to thewireless terminal. The second address assignment message includes amobility availability signal.

The address request message includes an extended access point name (APN)field. The extended APN field includes the mobility signal and an APNthat identifies a packet data network connected to the local mobilityagent. The address assignment message includes an extended access pointname (APN) field. The extended APN field includes a mobilityavailability signal and an APN that identifies a packet data networkconnected to the local mobility agent. The computer program furthercomprises including a same address signal in the address requestmessage. The same address signal indicates that multiple wirelessnetwork interfaces of the wireless terminal can be assigned a singleaddress; and forwarding the same address signal to the local mobilityanchor.

In still other features, the systems and methods described above areimplemented by a computer program executed by one or more processors.The computer program can reside on a computer readable medium such asbut not limited to memory, nonvolatile data storage, and/or othersuitable tangible storage mediums.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description, the claims and the drawings. Itshould be understood that the detailed description and specific examplesare intended for purposes of illustration only and are not intended tolimit the scope of the disclosure.

BRIEF DESCRIPTION OF DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a functional block diagram of a wireless communications systemaccording to the prior art;

FIG. 2 is a functional block diagram of a wireless communications systemoffering mobility according to the prior art;

FIG. 3 is a functional block diagram of a wireless communications systemaccording to the prior art that provides proxy mobility to a wirelessterminal;

FIG. 4 is a functional block diagram and timeline of an implementationof client mobility according to the prior art;

FIG. 5 is a functional block diagram and timeline of an implementationof proxy mobility according to the prior art;

FIGS. 6-8 are exemplary message flow diagrams for various methods ofobtaining a layer 3 address according to the prior art;

FIG. 9 is a functional block diagram of an exemplary communicationssystem according to the principles of the present disclosure;

FIGS. 10A-10D are exemplary portions of extended address configurationmessages according to the principles of the present disclosure;

FIGS. 11A-11B are exemplary extended address configuration messagesaccording to the principles of the present disclosure;

FIG. 11C is a representative field from the messages of FIGS. 11A-11Baccording to the principles of the present disclosure;

FIGS. 12A-12D are exemplary message flow diagrams according to theprinciples of the present disclosure;

FIG. 13 is a functional block diagram of an exemplary implementation ofthe wireless terminal according to the principles of the presentdisclosure;

FIGS. 14A-14C are flowcharts depicting exemplary operation of a wirelessterminal according to the principles of the present disclosure;

FIG. 15 is a functional block diagram of an exemplary communicationsystem for a wireless terminal having multiple interfaces according tothe principles of the present disclosure;

FIG. 16 is a functional block diagram of an exemplary implementation ofthe wireless terminal according to the principles of the presentdisclosure;

FIGS. 17A-17B are exemplary message flow diagrams for amultiple-interface wireless terminal according to the principles of thepresent disclosure;

FIG. 18 is a functional block diagram of an exemplary implementation ofthe media access gateway according to the principles of the presentdisclosure;

FIGS. 19A-19B are flowcharts depicting exemplary operation of a mediaaccess gateway according to the principles of the present disclosure;and

FIG. 20 is a functional block diagram of a mobile terminal according tothe principles of the present disclosure.

DESCRIPTION

The following description is merely exemplary in nature and is in no wayintended to limit the disclosure, its application, or uses. For purposesof clarity, the same reference numbers will be used in the drawings toidentify similar elements. As used herein, the phrase at least one of A,B, and C should be construed to mean a logical (A or B or C), using anon-exclusive logical or. It should be understood that steps within amethod may be executed in different order without altering theprinciples of the present disclosure.

As used herein, the term module refers to an Application SpecificIntegrated Circuit (ASIC), an electronic circuit, a processor (shared,dedicated, or group) and memory that execute one or more software orfirmware programs, a combinational logic circuit, and/or other suitablecomponents that provide the described functionality.

When a wireless terminal attaches to a visited network, the wirelessterminal may not know which types of mobility the visited networksupports. For example, mobility types may include proxy mobile IP (PMIP)and client mobile IP (CMIP). Similarly, the visited network may not beaware of the mobility capabilities of the wireless terminal.

Further, if the wireless terminal supports multiple mobility types, thevisited network may not know which mobility type the wireless terminalprefers. The mobility types that the visited network allows for thewireless terminal may depend upon a profile corresponding to thewireless terminal and/or to an agreement between the visited network anda home network of the wireless terminal.

According to the principles of the present disclosure, informationregarding mobility preferences and capabilities can be transmittedbetween the wireless terminal and the visited network. For example, amobility signal may be sent from the wireless terminal to the visitednetwork indicating what mobility types the wireless terminal supportsand which mobility types are preferred. The visited network may send amobility availability signal to the wireless terminal indicating whatmobility types are supported by the visited network and allowed for thewireless terminal.

For example only, these mobility preferences and capabilities may beincluded in address configuration messages. In various implementations,address configuration messages are used to configure a layer 3 addresswhen a node, like the wireless terminal, connects to a network.

Address configuration messages may include address request messages andaddress assignment messages. For example only, router solicitation androuter advertisement messages may serve as address request and addressassignment messages, respectively, when stateless addressautoconfiguration is used. For example only, dynamic host configurationprotocol (DHCP) messages may serve as address request and addressassignment messages when stateful address configuration is used. DHCPsolicit, discover, and request messages may serve as address requestmessages. DHCP reply, advertise, acknowledge, and offer messages mayserve as address assignment messages.

As described above, when using CMIP, the visited network provides acare-of address to the wireless terminal that the wireless terminal usesto directly establish a connection with the home network. When usingPMIP, the visited network provides transparent tunneling of packetsbetween the wireless terminal and the home network. Therefore, if awireless terminal does not or can not provide mobility information tothe visited network, the visited network may use PMIP by default.

Referring now to FIG. 9, a functional block diagram of an exemplarycommunications system is presented. A wireless terminal 202 connects toa media access gateway (MAG) 204. After establishing layer 2connectivity with the MAG 204, the wireless terminal 202 requests alayer 3 address.

The MAG 204 may access a profile associated with the wireless terminal202. The profile may be stored in a home subscriber server (HSS) 206.The profile may indicate which mobility types should be offered to thewireless terminal 202. The profile may also include home addressinformation and local mobility anchor address information. As describedin more detail below, the wireless terminal 202 and the MAG 204 exchangeinformation regarding mobility capabilities and preferences.

If the MAG 204 decides to provide PMIP to the wireless terminal 202, theMAG 204 sends a proxy binding update to a local mobility anchor (LMA)208. The address of the LMA 208 may have been obtained from the HSS 206.The LMA 208 responds with a proxy binding acknowledgement and the MAG204 sets up a tunnel to the LMA 208. The LMA 208 communicates with apacket data network 210. Packets from the wireless terminal 202 areencapsulated by the MAG 204 and tunneled to the LMA 208. They are thendecapsulated and sent to the packet data network 210. Similarly, packetsfrom the packet data network 210 are encapsulated by the LMA 208 andtunneled to the MAG 204. The packets are then decapsulated and sent tothe wireless terminal 202.

Referring now to FIGS. 10A-10D, exemplary portions of extended addressconfiguration messages are shown. In FIG. 10A, an extended message sentfrom a wireless terminal to a media access gateway is shown. Forexample, this message may be a router solicitation message and/or a DHCPmessage. The DHCP message may be known as a discover, request, orsolicit message.

The message may include an indication of which mobility modes aresupported, such as PMIP or CMIP. In addition, the message may indicatewhich mobility mode is preferred for the current connection. Further,the message may indicate which mobility mode will be preferred forfuture handoffs.

The message may also include an indication of whether the wirelessterminal desires to be assigned the same address as the wirelessterminal has been assigned before. For example, if the wireless terminalhas two interfaces and wants to maintain continuity when switching fromone interface to the other, the wireless terminal may request the sameaddress when the second interface connects to a network. Alternatively,the wireless terminal may indicate that a different address is desired.For example only, the wireless terminal may be unable to assign the sameaddress to both of its interfaces.

In FIG. 10B, an extended message sent from the media access gateway tothe wireless terminal is shown. This message may be a routeradvertisement message and/or a DHCP message, such as an offer,acknowledgement, advertise, or reply message. The message may includeindications of which mobility modes are allowed for the wirelessterminal. For example, a flag may be included indicating that PMIP isavailable.

In FIG. 10C, an extended message sent from the wireless terminal to themedia access gateway is shown. The message may be a router solicitationmessage or a DHCP message. The message may include an indication of thedesired mobility mode of the wireless terminal. In addition, the messagemay indicate whether a different address or the same address isrequested by the wireless terminal.

In FIG. 10D, an extended message is shown. For example, the message maybe a router advertisement or a DHCP message. The message may indicatethat PMIP is available and may include home address information. Forexample, this home address information may include a home address prefixand/or a home address. If the media access gateway is allowing thewireless terminal to conduct CMIP, the message may include a care-ofaddress or care-of address prefix. Care-of address information may alsobe included in the message when PMIP is used.

Referring now to FIGS. 11A-11C, exemplary extended address configurationmessages are shown in FIGS. 11A-11B, while a representative field fromthese messages is shown in FIG. 11C. In FIG. 11A, an extended message,such as a router advertisement or DHCP request message, includes anextended access point name (APN) field. An APN is a unique identifier ofa packet data network. The wireless terminal may provide an APN to amedia access gateway so that the media access gateway knows to which PDNthe wireless terminal desires to connect. An example of an extended APNis shown in FIG. 11C.

In FIG. 11B, an extended message, such as a router advertisement or DHCPreply, includes an extended APN field. In FIG. 11C, an exemplaryextended APN is shown. The extended APN includes mobility informationand may include the APN present in a standard APN field. For exampleonly, the extended APN may include indications of which mobility typesare supported and available.

In addition, information may be included to indicate a preference oravailability of mobility types for use in a handoff situation. Handoffsituations may occur when an interface of the wireless terminal switchesfrom one media access gateway to another. In addition, a handoff mayoccur between interfaces of a wireless terminal having multipleinterfaces. For example only, a wireless terminal may request PMIP forthe current connection and CMIP for a handoff using two extended APNs:“local_domain:pmip” and “home_domain:cmip”. If the media access gatewayresponds that either of these requests is not possible, the wirelessterminal may adapt its mobility request.

The extended APN may also include an indication of whether the wirelessterminal desires the same address to be assigned. Some or all of theinformation described with respect to the extended APN may be includedin any message sent between the wireless terminal and the media accessgateway. In various implementations, this information may be sent withinmessages that are already being exchanged for address configuration.

For example only, in this way, additional messages specific to mobilitysignaling are not necessary. Mobility information may be placed inpreexisting options or fields. Alternatively, new fields, options, andsub-options may be defined to store this information.

Referring now to FIGS. 12A-12D, exemplary message flow diagrams areshown. In FIG. 12A, the wireless terminal establishes a layer 2connection with a media access gateway (MAG). The wireless terminalbroadcasts a router solicitation message indicating that the wirelessterminal supports PMIP.

The MAG accesses a profile corresponding to the wireless terminal. Invarious implementations, the MAG may access the profile prior toreceiving the router solicitation message. If the access profileincludes a home address prefix for the wireless terminal, the MAG maytransmit that home address prefix to the wireless terminal in a routeradvertisement message. The router advertisement message may alsoindicate whether PMIP can be provided by the MAG.

The MAG transmits a proxy binding update to a local mobility anchor(LMA), the address of which may have been included in the profile. Theproxy binding update includes a unique identifier of the wirelessterminal, such as a mobile node ID (MN_ID). The MAG may transmit theproxy binding update as soon as the profile is accessed. If the homeaddress prefix is transmitted, the wireless terminal can performautoconfiguration to generate a full IP address based on the prefix.

Meanwhile, the LMA responds with a proxy binding acknowledgement to theMAG. The proxy binding acknowledgement may include a home addressprefix, which may differ from the prefix stored in the profile. A routeradvertisement message including the received home address prefix is thensent to the wireless terminal. This step may be skipped if the homeaddress prefix received from the LMA has already been sent to thewireless terminal.

If the new home address prefix is transmitted, the wireless terminalthen performs autoconfiguration based on the new home address prefix. Invarious scenarios, therefore, the wireless terminal may perform addressautoconfiguration twice. Session continuity may be lost during thesecond autoconfiguration. However, latency is reduced by providing anaddress to the wireless terminal as soon as possible.

Referring now to FIG. 12B, a message flow diagram where the MAG requiresthe wireless terminal to use DHCP is presented. After establishing layer2 connectivity, the wireless terminal broadcasts a router solicitationmessage to the MAG. The router solicitation message may include anindication that PMIP is supported and/or desired by the wirelessterminal. The MAG may access the profile corresponding to the wirelessterminal.

If autoconfiguration is not allowed for the wireless terminal, the MAGmay transmit a router advertisement message to the wireless terminalindicating that DHCP is required. In various implementations, theindication that DHCP is required may be sent to any wireless terminalthat connects to the MAG without first accessing the profile for thewireless terminal.

The wireless terminal then optionally sends a DHCP request to the MAGincluding an indication that PMIP is supported by the wireless terminal.The MAG optionally responds with a DHCP reply indicating that PMIP isavailable for the wireless terminal. The DHCP request and DHCP reply maybe known as a DHCP discover and a DHCP offer, respectively.

The wireless terminal then sends a DHCP request to the MAG indicatingthat PMIP is desired. If the profile for the wireless terminal includesaddress information, the MAG can provide address information to thewireless terminal at this point. If the profile includes a prefix, theMAG may configure a full IP address based on the prefix. The MAG maythen transmit a DHCP reply to the wireless terminal including thisaddress.

The DHCP reply may also indicate that PMIP is available and will beprovided for the wireless terminal. Meanwhile, the MAG sends a proxybinding update to the LMA. In various implementations, the MAG may sendthe proxy binding update as soon as the profile is accessed. The LMAresponds with a proxy binding acknowledgement. The proxy bindingacknowledgement may include updated address information, such as anupdated address prefix. The MAG may form a full IP address based on theprefix information. This address is then transmitted to the wirelessterminal in a DHCP reply. The DHCP reply may be omitted if the sameaddress had already been sent in the earlier DHCP reply.

Referring now to FIG. 12C, a message flow diagram depicts a wirelessterminal that requests CMIP. After the wireless terminal establisheslayer 2 connectivity with an access network, the access network may senda router advertisement to the wireless terminal indicating that DHCP isrequired. This router advertisement may be preemptively sent before anyrouter solicitation is received.

The wireless terminal broadcasts a DHCP request. The DHCP request mayindicate that CMIP is desired. In various implementations, theindication of CMIP may be included in an extended APN. If the accessnetwork will allow the wireless terminal to use CMIP, the access networkprovides a local IP address to the wireless terminal in a DHCP reply.

This local IP address may be globally routable, and allows the wirelessterminal to communicate with a home agent. The wireless terminal mayestablish an internet protocol security (IPsec) internet key exchange(IKE) security association (SA) with the home agent. After the SA isestablished, the wireless terminal transmits a binding update to thehome agent. The home agent responds with a binding acknowledgement,which may include the home address assigned to the wireless terminal.The wireless terminal and the home agent then establish a tunnel forexchanging packets between the wireless terminal and a packet datanetwork associated with the home agent.

Referring now to FIG. 12D, an exemplary message flow diagram depicts asituation where the wireless terminal does not provide mobilityinformation. First, layer 2 connectivity is established between thewireless terminal and the MAG. The wireless terminal may broadcast arouter solicitation message and/or a DHCP request. Meanwhile, the MAGaccesses the profile corresponding to the wireless terminal.

If the MAG does not receive any mobility information from the wirelessterminal within a predetermined time period, the MAG may assume thatPMIP should be provided to the wireless terminal. The MAG thereforesends a proxy binding update to the LMA. Once a proxy bindingacknowledgement is received from the LMA, the MAG provides the assignedhome address information to the wireless terminal. This home addressinformation may include a home address prefix and/or a full homeaddress. In various implementations, home address information found inthe profile may have been sent to the wireless terminal prior to theproxy binding acknowledgement being received.

Referring now to FIG. 13, a functional block diagram of an exemplaryimplementation of the wireless terminal 202 is presented. The wirelessterminal 202 includes a wireless network interface 302 that transmitsand receives wireless signals using an antenna 304. An applicationmodule 306 sends and receives data using the wireless network interface302. For example only, the application module 306 may transmit andreceive voice over IP (VoIP) data, text messaging data, push e-maildata, world wide web browsing data, etc.

An address determination module 308 determines an address to be assignedto the wireless network interface 302. This address will be used as thesource address for packets transmitted by the wireless network interface302. The address determination module 308 may cause the wireless networkinterface 302 to transmit DHCP requests and/or router solicitationmessages. Responses, such as DHCP replies and router advertisementmessages, are sent to the address determination module 308.

A mobility control module 310 determines a desired mobility mode, andindicates this mode to the address determination module 308. The addressdetermination module 308 then provides an indication of this desiredmobility mode to the network to which the wireless network interfaceconnects. The mobility control module may determine the desired mobilitymode by consulting with the application module 306.

Referring now to FIGS. 14A-14C, flowcharts depict exemplary operation ofa wireless terminal. In FIG. 14A, control begins in step 402, wherelayer 2 connectivity is established with the visited network. Controlcontinues in step 404, where a router solicitation message is broadcast.The router solicitation message indicates that PMIP is supported by thewireless terminal. In various implementations, an indication that PMIPis supported may be equivalent to an indication that PMIP is desired bythe wireless terminal.

Control continues in step 406, where control waits for a routeradvertisement message. If the router advertisement message indicatesthat DHCP is required, control transfers to step 408; otherwise, controltransfers to step 410. In step 410, control uses the prefix received inthe routing advertisement message to determine an IP address. Controlthen continues in step 412.

In step 408, control broadcasts a DHCP request indicating that PMIP issupported. Control continues in step 414, where control waits for a DHCPreply to be received. Once the DHCP reply is received, control transfersto step 412. In step 412, an IP address is assigned to the networkinterface of the wireless terminal. This address is either determined instep 410 or received in the DHCP reply in step 414.

Control continues in step 416, where control determines whether anadditional DHCP reply has been received. If so, the additional DHCPreply includes a replacement address, and control transfers to step 418.Otherwise, control continues in step 420. In step 420, controldetermines whether an additional router advertisement message has beenreceived. If so, the router advertisement includes a replacement prefixand control transfers to step 422. Otherwise, control returns to step416. In step 422, control uses the prefix received in the routeradvertisement message to determine a new IP address. In step 418,control assigns the new IP address to the network interface of thewireless terminal. Control then ends.

Referring now to FIG. 14B, an exemplary flowchart depicts a two-stageDHCP message exchange. After the DHCP reply is received in step 414,control transfers to step 450. In step 450, control broadcasts a DHCPrequest indicating that PMIP is desired. In various implementations, theDHCP request may be transmitted directly to the media access gateway.Control then continues in step 452, where control waits for another DHCPreply to be received. Once the DHCP reply is received, control transfersto step 412. The DHCP reply received in step 452 includes the assignedaddress information, while the DHCP reply received in step 414 maysimply include an indication of PMIP support.

Referring now to FIG. 14C, an exemplary flowchart depicts operation whenthe wireless terminal desires to use CMIP. Control begins in step 402,where layer 2 connectivity is established. Control continues in step502, where a router solicitation message is broadcast indicating thatCMIP is desired. Control continues in step 504, where control waits fora router advertisement to be received. If the router advertisementindicates that DHCP is required, control transfers to step 506;otherwise, control transfers to step 508.

In step 506, control transmits a DHCP request indicating that CMIP isdesired. Control continues in step 510, where control waits for a DHCPreply to be received. Once the DHCP reply has been received, controltransfers to step 512. In step 508, control determines an IP addressbased upon the prefix received in the router advertisement. Controlcontinues in step 512.

In step 512, control assigns the IP address to the network interface ofthe wireless terminal. Control continues in step 514, where controldetermines whether CMIP is allowed. If so, control transfers to step 516to begin direct contact with a home agent. Otherwise, CMIP is notallowed and mobility will be provided by the visited network, so controlends. Whether CMIP is allowed may be determined from received routeradvertisements and/or DHCP replies.

In step 516, control establishes a connection with the home agent.Control continues in step 518, where control transmits a binding updateto the home agent. In step 520, control waits for a bindingacknowledgement to be received. Control continues in step 522 where atunnel is set up to the home agent. Control then ends.

Referring now to FIG. 15, a functional block diagram of an exemplarycommunication system for a wireless terminal having multiple interfacesis depicted. A wireless terminal 602 includes two interfaces, whichestablish layer 2 connectivity with a first media access gateway (MAG)604 and a second MAG 606. The first and second MAGs 604 and 606 may bothprovide proxy mobility for the wireless terminal 602 and connect to alocal mobility anchor 608.

The first and second MAGs 604 and 606 may obtain profile informationcorresponding to the wireless terminal 602 from the home subscriberserver (HSS) 206. The local mobility anchor 608 serves as a gateway to apacket data network 610. The multiple interfaces of the wirelessterminal 602 may be of the same type, such as both being cellularinterfaces. Alternatively, one interface may be cellular while anotheris a wireless local area network (such as WiFi, IEEE 802.11).

Referring now to FIG. 16, a functional block diagram of an exemplaryimplementation of the wireless terminal 602 is presented. The wirelessterminal 602 includes first and second wireless network interfaces 650and 652. The first and second wireless network interfaces 650 and 652transmit and receive wireless signals using first and second antennas654 and 656, respectively. In various implementations, a single antennamay be used for both the first and second wireless network interfaces650 and 652.

An application module 660 sends and receives data via the first andsecond wireless network interfaces 650 and 652. First and second addressdetermination modules 662 and 664 determine addresses assigned to thefirst and second wireless network interfaces 650 and 652, respectively.A mobility control module 670 provides information about supported anddesired mobility modes to the first and second address determinationmodules 662 and 664.

Referring now to FIGS. 17A-17B, exemplary message flow diagrams for amultiple-interface wireless terminal are presented. In FIG. 17A, a firstinterface of the wireless terminal has already established a PMIPconnection with a first access network, access network A. Access networkA therefore has a tunnel to a local mobility anchor (LMA) established.

A second interface of the wireless terminal then establishes layer 2connectivity with a second access network, access network B. If accessnetwork B receives no mobility information from the wireless terminal,access network B may provide PMIP by default. Access network B may beable to request from the LMA the same address that is already assignedto interface 1. In this case, the address assigned to interface 1 isshown as HoA (home address).

Some wireless terminals may be unable to assign the same address to bothinterfaces. Other wireless terminals may enter an indeterminate statewhen the same address is assigned to both interfaces. Access network Bmay therefore request a new address from the LMA unless the wirelessterminal has provided some indication that the same address should beassigned to the second interface.

Access network B then sends a proxy binding update to the LMA indicatingthat a new address should be assigned to the second interface of thewireless terminal. The LMA responds with a proxy binding acknowledgementincluding a new home address, HoA′. Access network B then provides HoA′to the wireless terminal. The wireless terminal then assigns thereceived home address (HoA′) to the second interface, and a PMIP tunnelis established between access network B and the LMA.

In various implementations, the proxy binding acknowledgement mayinclude an address prefix, which is used to configure a full address,instead of a full address. Address prefixes may be used with addressautoconfiguration. When the first interface configured its address usingautoconfiguration, the address likely included a unique interfaceidentifier. Therefore, if the address for the second interface is alsoautoconfigured, the different interface identifier for the secondinterface should lead to a different address being created, even if thesame prefix is used. If the current address is determined by DHCP, aslong as the MAG does not intentionally provide the addressautoconfigured by the first interface, the second interface will have adifferent address.

Another scenario is where the first interface configured its addressusing DHCP. In this case, if the address for the second interface isautoconfigured, the unique interface identifier of the second interfaceshould result in a new address being configured. Only in the case wherethe addresses of both the first and second interfaces are configuredwith DHCP could the interfaces inadvertently receive the same address.This is the situation that the MAG may avoid if no explicit indicationis received from the wireless terminal regarding whether the twoaddresses can be the same.

In various implementations, access network B may not determine whether anew address or the same address should be assigned to the wirelessterminal. The LMA, however, may realize that a first interface hasalready established connectivity. The LMA may therefore decide whetherto assign the same address or address prefix to the second interface.For example only, this decision may be based upon profile informationfor the wireless terminal. If the profile indicates that the wirelessterminal can accommodate the same address on multiple interfaces, theLMA may provide the same address information to access network B thatwas provided to access network A.

Referring now to FIG. 17B, the first interface of the wireless terminalhas already established a connection with access network A when thesecond interface of the wireless terminal establishes layer 2connectivity with access network B. In FIG. 17B, however, the wirelessterminal indicates to access network B that PMIP is supported.Indicating that PMIP is supported may also serve as an indication thatthe wireless terminal can accommodate the same address and multipleinterfaces.

Alternatively, an additional piece of information may be sent from thewireless terminal to the access network B to indicate that the sameaddress can be used. Access network B therefore transmits a proxybinding update to the LMA indicating that the same address should beprovided. The LMA responds to the proxy binding acknowledgement, whichmay include the same address (HoA) that was provided to access networkA.

Referring now to FIG. 18, a functional block diagram of an exemplaryimplementation of the MAG 204 is presented. The MAG 204 includes anetwork processor 702 that communicates with a packet data network via anetwork interface 704. A wireless network interface 706 communicateswith a wireless terminal via an antenna (not shown).

The MAG 204 also includes an address assignment module 710, a proxymobility agent (PMA) module 712, a profile determination module 714, anda tunneling module 716. The address assignment module 710 processesmessages, such as DHCP requests and router solicitation messages.

The address assignment module 710 also generates messages, such as DHCPreplies and router advertisement messages. In various implementations,the address assignment module 710 may send and receive extended versionsof these messages, such as are shown in FIGS. 10A-11B. The addressassignment module 710 provides information regarding the mobilitycapability and preferences of the wireless terminal through the PMAmodule 712.

The PMA module 712 indicates to the address assignment module 710 themobility capabilities of the MAG 204. The address assignment module 710may include these capabilities in messages transmitted to the wirelessterminal. The PMA module 712 may determine which mobility modes areallowed for the wireless terminal based on profile information from theprofile determination module 714.

The profile determination module 714 may obtain profile information forthe wireless terminal from a remote source, such as a home subscriberserver. The profile information may be indexed by a unique identifier ofthe wireless terminal. Additional profile information may correspond tothe network in which the MAG 204 resides and/or profile informationrelating to the relationship between that network and a home network ofthe wireless terminal. The PMA module 712 establishes a tunnel betweenthe MAG 204 and one or more LMAs using the tunneling module 716.

Referring now to FIGS. 19A-19B, flowcharts depict exemplary operation ofthe media access gateway. In FIG. 19A, control begins in step 802, wherecontrol waits for layer 2 connectivity to be established by the wirelessterminal. Control then transfers to step 804. In step 804, controldetermines whether a router solicitation message has been received. Ifso, control transfers to step 806; otherwise, control transfers to step808.

Control may wait a predetermined period of time before transferring tostep 808. After that predetermined period of time, control may assumethat no router solicitation will be received and that proxy mobilityshould be provided. In step 806, control determines whether the routersolicitation message indicated that CMIP was desired by the wirelessterminal. If so, control transfers to step 810; otherwise, controltransfers to step 808. If no mobility information is included in therouter solicitation message, control may also transfer to step 808.

In step 810, control transmits a router advertisement message to thewireless terminal. The router advertisement message includes a care-ofaddress prefix from which the wireless terminal can create a care-ofaddress. Using that care-of address, the wireless terminal cancommunicate with a home agent. Control then ends.

In step 808, control determines whether the prefix information for thewireless terminal is stored in the wireless terminal's profile. If so,control transfers to step 812. Otherwise, control transfers to step 814.In step 812, control optionally transmits a router advertisement messageincluding the prefix information from the profile. Control continues instep 814. In step 814, control transmits a proxy binding update to theLMA corresponding to the wireless terminal.

Control continues in step 816, where control remains until a proxybinding acknowledgement is received. Control then transfers to step 818.In step 818, control transmits a router advertisement to the wirelessterminal. Step 818 may be skipped if a router advertisement message wastransmitted in step 812 and the address information received in theproxy binding update does not differ from what was transmitted in step812. Control then ends.

Referring now to FIG. 19B, control begins in step 902, where controlremains until layer 2 connectivity is established with the wirelessterminal. Control then transfers to step 904, where control determinesif a router solicitation message has been received. If so, controltransfers to step 906; otherwise, control transfers to step 908. Ifafter a predetermined period of time no router solicitation is received,control may transfer to step 908.

In step 906, a router advertisement message indicating that DHCP isrequired is sent in response to the router solicitation message. Controlthen continues in step 908. In step 908, control waits for a DHCPrequest to be received. Once the DHCP request is received, controldetermines whether that request indicates PMIP support. If so, controltransfers to step 910; otherwise, control transfers to step 912.

In step 912, control determines whether the DHCP request indicates apreference for CMIP. If so, control transfers to step 914; otherwise,control transfers to step 910. Control transfers to step 910 because theDHCP request does not indicate either PMIP or CMIP support, andtherefore PMIP will be provided.

In step 914, control transmits a DHCP reply including a care-of address.Control then ends. In step 910, control transmits a DHCP replyindicating that PMIP is available for a wireless terminal. Control thencontinues in step 916, where control waits for a DHCP request to bereceived. If the request indicates that PMIP is desired, controltransfers to step 918; otherwise, control transfers to step 914. Steps910 and 916 may be omitted, and the wireless terminal therefore does nothave to confirm its desire to use PMIP.

In step 918, control determines whether home address information isstored in the profile corresponding to the wireless terminal. If so,control transfers to step 920; otherwise, control transfers to step 922.In step 920, home address information is already known, and it maytherefore be transmitted to the wireless terminal. Control thencontinues in step 922.

In step 922, control transmits a proxy binding update to the LMAcorresponding to the wireless terminal. Control continues in step 924,where control waits for the proxy binding acknowledgement to bereceived. Once the proxy binding acknowledgement is received, controltransfers to step 926. In step 926, control transmits a DHCP replyincluding the received home address information to the wirelessterminal. Control may omit step 926 when the received home addressinformation does not differ from information already transmitted in step920.

Referring now to FIG. 20, the teachings of the disclosure can beimplemented in a control module 1060 of a mobile terminal 1058. Themobile terminal 1058 includes the control module 1060, a power supply1062, memory 1064, a storage device 1066, and a wireless networkinterface 1067. The mobile terminal 1058 may optionally include anetwork interface 1068, a microphone, an audio output such as a speakerand/or output jack, a display 1074, and a user input device 1076 such asa keypad and/or pointing device. If the network interface 1068 includesa wireless local area network interface, an antenna (not shown) may beincluded.

The control module 1060 may receive input signals from the wirelessnetwork interface 1067, the network interface 1068, the microphone,and/or the user input device 1076. The control module 1060 may processsignals, including encoding, decoding, filtering, and/or formatting, andgenerate output signals. The output signals may be communicated to oneor more of memory 1064, the storage device 1066, the wireless networkinterface 1067, the network interface 1068, and the audio output.

Memory 1064 may include random access memory (RAM) and/or nonvolatilememory. Nonvolatile memory may include any suitable type ofsemiconductor or solid-state memory, such as flash memory (includingNAND and NOR flash memory), phase change memory, magnetic RAM, andmulti-state memory, in which each memory cell has more than two states.The storage device 1066 may include an optical storage drive, such as aDVD drive, and/or a hard disk drive (HDD). The power supply 1062provides power to the components of the mobile terminal 1058. Theteachings of the disclosure can be implemented similarly in otherdevices such as a personal digital assistant, a media player, a laptopcomputer, a gaming console, or other mobile computing device.

Those skilled in the art can now appreciate from the foregoingdescription that the broad teachings of the disclosure can beimplemented in a variety of forms. Therefore, while this disclosureincludes particular examples, the true scope of the disclosure shouldnot be so limited since other modifications will become apparent upon astudy of the drawings, the specification, and the following claims.

What is claimed is:
 1. A media access gateway comprising: a wirelessnetwork interface configured to establish a wireless link with awireless terminal; an address assignment module configured to receive anaddress request message from the wireless terminal, the address requestmessage including a mobility signal; a proxy mobility agent moduleconfigured to (i) selectively transmit a proxy binding update to a localmobility anchor, and (ii) receive a proxy binding acknowledgement fromthe local mobility anchor; and a profile module configured to retrieve aprofile corresponding to the wireless terminal from a server, whereinthe address assignment module is configured to selectively transmit anaddress assignment message to the wireless terminal in response to themobility signal indicating at least one of (i) support for proxymobility or (ii) a preference for proxy mobility, wherein the addressassignment message is based on address information in the proxy bindingacknowledgement, and wherein the address assignment module is configuredto, in response to the profile including address information for thewireless terminal, transmit a second address assignment message to thewireless terminal based on the address information in the profile. 2.The media access gateway of claim 1, wherein: the address requestmessage comprises at least one of a dynamic host configuration protocol(DHCP) message and a router solicitation message; and the addressassignment message comprises at least one of a DHCP message and a routeradvertisement message.
 3. The media access gateway of claim 1, whereinthe proxy mobility agent module is configured to, in response to theaddress information in the proxy binding acknowledgement matching theaddress information in the profile, omit transmitting the addressassignment message.
 4. The media access gateway of claim 1, wherein theproxy mobility agent module is configured to determine an address of thelocal mobility anchor from the profile.
 5. The media access gateway ofclaim 1, wherein the address assignment module is configured to receivea second address request message prior to receiving the address requestmessage, and wherein the second address request message includes amobility request signal.
 6. The media access gateway of claim 5, whereinthe address assignment module is configured to, in response to receivingthe second address request message, transmit a second address assignmentmessage to the wireless terminal, wherein the second address assignmentmessage includes a mobility availability signal.
 7. The media accessgateway of claim 1, wherein the address request message includes anextended access point name (APN) field, and wherein the extended APNfield includes the mobility signal and an APN that identifies a packetdata network connected to the local mobility anchor.
 8. The media accessgateway of claim 1, wherein the address assignment message includes anextended access point name (APN) field, wherein the extended APN fieldincludes a mobility availability signal and an APN that identifies apacket data network connected to the local mobility anchor.
 9. Acommunications system comprising: the media access gateway of claim 1;and a wireless terminal comprising: a second wireless network interface;and an address determination module configured to (i) transmit theaddress request message via the second wireless network interface, and(ii) receive the address assignment message via the second wirelessnetwork interface.
 10. The communications system of claim 9, wherein thewireless terminal further comprises a third wireless network interface,wherein the address determination module includes a same address signalin the address request message, wherein the same address signalindicates that the second and third wireless network interfaces can beassigned a single address, and wherein the proxy mobility agent moduleis configured to forward the same address signal to the local mobilityanchor.
 11. A method comprising: establishing a wireless link with awireless terminal; receiving an address request message from thewireless terminal, the address request message including a mobilitysignal; selectively transmitting a proxy binding update to a localmobility anchor; receiving a proxy binding acknowledgement from thelocal mobility anchor; selectively transmitting an address assignmentmessage to the wireless terminal in response to the mobility signalindicating at least one of (i) support for proxy mobility or (ii) apreference for proxy mobility; retrieving a profile corresponding to thewireless terminal from a server; and in response to the profileincluding address information for the wireless terminal, transmitting asecond address assignment message to the wireless terminal based on theaddress information in the profile, wherein the address assignmentmessage is based on address information in the proxy bindingacknowledgement.
 12. The method of claim 11, wherein: the addressrequest message comprises at least one of a dynamic host configurationprotocol (DHCP) message and a router solicitation message; and theaddress assignment message comprises at least one of a DHCP message anda router advertisement message.
 13. The method of claim 11, furthercomprising, in response to the address information in the proxy bindingacknowledgement matching the address information in the profile,omitting transmitting the address assignment message.
 14. The method ofclaim 11, further comprising determining an address of the localmobility anchor from the profile.
 15. The method of claim 11, furthercomprising receiving a second address request message including amobility request signal prior to receiving the address request message.16. The method of claim 15, further comprising, in response to receivingthe second address request message, transmitting a second addressassignment message to the wireless terminal, wherein the second addressassignment message includes a mobility availability signal.
 17. Themethod of claim 11, wherein the address request message includes anextended access point name (APN) field, and wherein the extended APNfield includes the mobility signal and an APN that identifies a packetdata network connected to the local mobility anchor.
 18. The method ofclaim 11, wherein the address assignment message includes an extendedaccess point name (APN) field, wherein the extended APN field includes amobility availability signal and an APN that identifies a packet datanetwork connected to the local mobility anchor.
 19. The method of claim11, further comprising: including a same address signal in the addressrequest message, wherein the same address signal indicates that multiplewireless network interfaces of the wireless terminal can be assigned asingle address; and forwarding the same address signal to the localmobility anchor.
 20. A computer program stored on a non-transitorycomputer-readable medium for use by a processor, the computer programcomprising: establishing a wireless link with a wireless terminal;receiving an address request message from the wireless terminal, theaddress request message including a mobility signal; selectivelytransmitting a proxy binding update to a local mobility anchor;receiving a proxy binding acknowledgement from the local mobilityanchor; selectively transmitting an address assignment message to thewireless terminal in response to the mobility signal indicating at leastone of (i) support for proxy mobility or (ii) a preference for proxymobility; retrieving a profile corresponding to the wireless terminalfrom a server; and in response to the profile including addressinformation for the wireless terminal, transmitting a second addressassignment message to the wireless terminal based on the addressinformation in the profile, wherein the address assignment message isbased on address information in the proxy binding acknowledgement.